John Fleming

John Calvin Fleming Jr. (Born 1951) is Louisiana's state treasurer and a former Republican congressman who served Louisiana's 4th congressional district from 2009 to 2017. A physician by training, he completed a family medicine residency with the US Navy, established a private practice in Minden, Louisiana, and built a franchise business employing over 350 people. In Congress he was one of the founding members of the House Freedom Caucus, placing him on the movement-conservative wing of the Republican Party well before the Trump era. After leaving the House he served in Trump's first administration, including as Deputy Chief of Staff in the West Wing in 2020. He won the 2023 Louisiana Treasurer runoff with over 65% of the vote and has served as state treasurer since January 2024.

In the 17 May 2026 Republican primary for Louisiana's Senate seat, Fleming finished second with 28.3% behind Trump-endorsed Julia Letlow (44.8%), setting up a 27 June 2026 runoff. Incumbent Bill Cassidy finished third with 24.8% and was thus eliminated, becoming the first elected incumbent senator to lose renomination since Richard Lugar in 2012. As the runoff drew near, Fleming surged from a deficit of roughly 15 points (Kaplan, early June) to near-parity: a Rigamer poll taken 15-16 June put Letlow at 40.2% against Fleming's 38.2%, inside the margin of error. Fleming made that ground on almost no outside money; by contrast, the pro-Letlow Accountability Project super PAC committed more than $6 million in independent expenditures across the runoff window, including a $1 million filing on 5 June 2026. Letlow declined Fleming's challenge to three debates, citing time with voters.

Regardless of the 27 June outcome, Louisiana's Senate seat will move further right: both Letlow and Fleming are aligned with Trump's political project, and neither faces a meaningful general-election contest in a state Trump won by a wide margin. Fleming's PATH to the Senate would represent the House Freedom Caucus's founding generation completing a transition from legislative insurgency to institutional control. His campaign is one of two Trump-aligned primaries that ousted establishment Republican senators within twelve days in May 2026, the other being Ken Paxton's defeat of John Cornyn in Texas.